1. Field of the Invention
This invention relates to silver halide, wash-out elements and more particularly to wash-out elements in which the imaged areas are hardened by a tanning development step. Still more particularly, this invention provides an improved silver halide, wash-out element wherein the distinction between the imaged and non-imaged areas is improved by the inclusion of polymer droplets in the wash-out element.
2. Background of the Invention
Photographic, gelatino-silver halide elements useful in wash-out systems are well-known in the art. These elements conventionally contain a gelatino-silver halide emulsion layer and optionally contain carbon black to generate high density images. A separate, high tinctorial layer with a colorant such as a pigment or carbon black, for example, also may be employed.
Wash-out elements are used by exposing the element to the desired pattern of actinic radiation to create a latent image in the element. This is typically accomplished by exposure through a mask or by modulating the source of radiation. The latent image is then developed using a tanning developer solution that hardens exposed regions of the emulsion layer without hardening the non-exposed regions. The unhardened gelatin is then washed out with an aqueous solution to leave the desired image.
Carbon black frequently is incorporated in the emulsion layer to permit reduction in the amount of silver employed, thereby reducing cost of the wash-out element, as disclosed in U.S. Pat. No. 4,233,392 to Friedel. Other recent improvements to wash-out elements include the incorporation of amine compounds and complexes to stabilize the elements against premature hardening, as disclosed in U.S. Pat. No. 4,456,676 to Ciskowski.
Despite the many improvements in wash-out elements made over the years, image integrity is still subject to deterioration during the wash-out step. It is desired that the final image have sharp edges. However, the wash-out step tends to be less selective at the boundary of imaged and non-imaged regions of the emulsion, which may cause a blurring of the image. This tendency has more severe results when the wash-out solution is sprayed onto the element at high velocity, as in higher-speed commercial developers, where the spray may undercut the imaged regions if it impacts the element at an angle. Thus, there is a need for further improvements to such wash-out elements.